


Teeth and madness

by CJaneway



Category: Death Note & Related Fandoms, Death Note (Anime & Manga)
Genre: Alternate Universe, Alternate Universe - Canon Divergence, Anal Birth, Anal Gaping, Anal Play, Anal Sex, Ass Birth, Blood, Blood Drinking, Blood Magic, Breeding, Cannibalism, Dilators, Dildos, Fuck Or Die, Graphic Birth Scene, Graphic Description, I am not ok neither is this fic if you are easy to squick get out quick, Implied Mpreg, Light and Ryuk eat their Shinigami Larvae offspring to gain more power, Lube, M/M, Magic, Mpreg, Non-Graphic Rape/Non-Con, Shinigami, Shinigami Eating Other Shinigami for Power, Shinigami Eyes, Shinigami Light, Shinigami Magic, Size Kink, World Domination
Language: English
Status: Completed
Published: 2019-02-14
Updated: 2019-02-15
Packaged: 2019-10-28 13:46:43
Rating: Explicit
Warnings: Graphic Depictions Of Violence, Rape/Non-Con
Chapters: 3
Words: 8,611
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/17788526
Author URL: https://archiveofourown.org/users/CJaneway/pseuds/CJaneway
Summary: I am not ok, neither is this fic, if you are easy to squick, please get out, quick.The King of Death is mad at Ryuk, and in a bid to punish him, involved Light. In response the two decide to mate, hatch a plan to overthrow his power, and eat their own Shinigami larvae to gain power.The rape is mentioned in conversation and thought, not explicit.





	1. The start of something gross

**Author's Note:**

> So hello. This has to be the most fucked up shit I've written in my entire life, from start to now, this has to be the actual crowning achievement of absolute stank ass fuckery I've produced. Like woah. I need to chill out and do something about this mind of mine; I am not ok, neither is this fic, if you are easy to squick, please get out, quick.

Ryuk was bored. Incredibly so. The apple bowl was empty, the snack stash Light pretended he didn’t have was empty, the house was empty – well, mostly, Light was hyper-focused on writing down the names of criminal scum and other undesirables. Ryuk had been thoroughly entertained by Light’s ambition and watching him, while both helping and hindering. It had been the most fun Ryuk had experienced in a long time; the problem was that, between the intense bouts of action where Light went head to head with either L or other obstacles that threatened his grand utopian vision, the monotonous drudgery almost drove Ryuk mad; it was almost worse than playing cards in the Shinigami realm without sleeper skulls to bet with.

Seriously, this was awful, and with the last lingering taste of the cyanide apple seeds settling in between his teeth, Ryuk felt the ashy flavor of listlessness creep back over his being like an unwelcome blanket on a hot day. The Shinigami was just about to do something to pester Light, which was always a good source of amusement – that boy was highly strung and deeply narcissistic, but his earring began heating up, almost burning the ear it pierced. The king was summoning him.

“Oy, Light-o, I’m being summoned by the King, I’ll be back whenever.” Ryuk wasn’t even sure that little megalomaniac even heard him over the sound of his own ego being expanded on paper, but the confused squawk he heard as he stepped through the portal between worlds was a great confirmation. The Shinigami was convinced that Light’s asshole was wound so tight he squeaked when he farted – not that he’d ever heard Light do anything of the sort outside of a bathroom, that little shit breathed dignity and honor to the point of noxiousness. He was still wildly entertaining, but Ryuk always knew he could crush this self-styled God with a pen-stroke, quite literally – well, entertaining and a constant supplier of apples. Apples were the food of the Gods, death gods as it were.

“Ryuk!” The booming voice of the King of Death was the first thing that greeted him when he landed back in the realm of death, already feeling how the dust settled in the crevices of his body. The huge mass of chains, limbs and skulls affectionately called “Old man” was the oldest, and purportedly wisest, Shinigami in existence: the keeper of books, and keeper of keys, the master of the realm. Even high tier Shinigami like Ryuk could stand against him.

“Sup, old man.” Ryuk greeted, respect or no, using titles for every day when you were literally stuck together for eternity got old real fast.

“You’ve been busy.” The King declared with the certainty of someone with labelled proof at hand.

“Yeah, ain’t been bored.” Ryuk answered noncommittally, hoping that he wasn’t in too much shit; the last time he pissed off the king he was locked away for two hundred years, just shy of dying from lack of life force, and bored out of his misshapen skull.

“I’ve talked to Sidoh.” _‘Oh fuck’_ Ryuk thought. “He’s looking for something, a lost possession of sorts – have you seen it?” The king continued in that same, smug voice “Touched it, perhaps, or handed it over to an overzealous human?” _‘Shit’_ Ryuk could feel the walls of the containment chambers closing in on him already.  “I would have tossed your ass into a cell for another few centuries for this shit, Ryuk, you know better, but there’s a problem.” Ryuk was torn between utter relief at escaping a cell and clenching up Light-style at the potential problem. “You see, your _overzealous_ human has the potential to become a breeder.” _‘Oh, fuck me’_ , Ryuk felt faint for the first time since he’d defeated and eaten enough lesser Shinigami to cobble together a consciousness of his own – he’d eaten a lot of Shinigami since then. “A grand total of eight thousand four hundred and eighty-two, wait, eighty-three as of this second – a prolific little shit, isn’t he?” Wow, Ryuk really hadn’t been paying attention, that was a lot!

“Wow.” Ryuk said, that was respectable, even Shinigami respectable – he knew, personally, at least three Shinigami with lower kill counts than that.

“Exactly. Which means that this little boy of yours has accumulated enough spiritual energy to create a good many Shinigami, and I want more.” The king almost looked gleeful, or as much as a huge ball of skulls and chains could and pointed a gangly limb at the Shinigami in front of him. “Now, what I want you to do is breed the boy, and when I say want, I do mean command, Ryuk, you’ve eaten more than your fair share of Shinigami to further your strength, and you’ve got enough lifespan stacked up to where imprisoning you would be useless. I, as your king, and the holder of your Death Note privileges, am revoking your right to write in your Death Note, any name will disappear, and only when you’ve mated the boy do you get them back.” Ryuk almost looked relieved - fucking Light would be easy, it wouldn’t be the first human he’d spirited away for some rough and tumble, they all gave up in the end – crying humans turned Ryuk on, if he was honest. “Oh, and Ryuk? If the boy dies, you die, and he has to be willing.” _‘You bastard’_ Ryuk hissed inside his own mind as he heard the last criteria; how the fuck was he supposed to get Light to actually agree to getting mated by a Shinigami?

“You’ve pissed me off for the last time, Ryuk, hopefully your ugly ass has enough charm to turn that angelic little serial killer into a willing mate.” Ryuk would have preferred a cell to this – this was a sure death sentence! If Light and L continued to circle around each other like wolves he would soon be out of time!

“If I kill someone to protect Light?” He croaked, because that seemed to be more and more likely of a scenario – god he hated this.

“The rules still apply.” The Shinigami king cackled as he spoke, his words sealing Ryuk’s doom. “You can’t tell him of the benefits of becoming a mate either.” The king said, and Ryuk knew it to be true as he _felt_ the rules get inscribed into his own note. A Death God was intimately bound to their Death Note, even after its ownership had passed to other gods or humans, and the bond took a while to weaken. As the King spoke Ryuk could feel his own book withdrawing the bond, and it made him feel naked, vulnerable. Light would have jumped at being mated, Ryuk realized, if he could tell him that becoming a mate had many perks such as the eyes, wings, and bonded immortality, amongst others, which meant that Light wouldn’t die unless Ryuk did, but with the stipulations in place, Ryuk had to attempt the impossible; manipulate a socially clever narcissist into loving someone other than himself.

“You’re an absolute ass, old man.” Ryuk ground out. The King laughed so hard the sound of rattling chains drowned out all other sounds for a good while.

“I am, but you’ve brought it on yourself.” The King declared, “Also, I’ve bonded Sidoh to a new book, your little pet can keep his, it will become his if he deigns to bond with you. After what I’ve seen I’ve got one last thing to say: good luck!” Ryuk growled and went back to the human world – if he was going to die, at least he would eat all the damn apples he could before croaking it. Fucking king. As he left through a portal all he heard was the gleeful cackling of his bastard King, which rankled him deeply.

“So, what did the king want?” Light had turned around on his office chair the moment Ryuk reappeared, apparently done with doling out judgement for the day.

“Nothing.” Ryuk deflected as he moved towards the bowl of apples, before realizing it was empty. “We’re out of apples.” He said.

“I’ll get you some if you tell me what the King wanted.” Light countered, because he was an absolute terror when it came to figuring things out, and Ryuk, while being an actual god, was not infallible enough to want to test his mettle against Light’s intellect when his own life was on the line. He couldn’t kill the little shit either. God-damn the King of Death was an asshole, a complete, one hundred percent, unrepentant asshole – he looked like one too. He looked like the malformed bony asshole of some of the eviler figures in human mythology. Ryuk took no comfort in disparaging the King’s appearance when faced with Light’s inquisitive glare and knowing he’d have to make that boy unclench enough to be able to get between those thighs to spare his own life.

“I can’t” Ryuk decided that being as honest as he could was a good idea. “I’ve got orders from the Shinigami King, but if I tell you I die.” He admitted, his fingers were itching to just grab Light and get it over with, but that was a sure death sentence too.

“Do the orders affect me?” Was Lights next question, and Ryuk could have cursed the high heaven for days – why the King wanted him to breed a genius with delusions of grandeur, honestly, Ryuk could have found another psychopath and just forced them to write for days before fucking them ragged and wringing each ounce of spirit energy out of them, but no, he had to seduce a prissy genius without telling him why.

“They do.” Ryuk admitted and could almost muster up some glee at the look of consternation that crossed Light’s face – yet his own impending doom curbed his mirth something awful.   

“Well, it doesn’t involve killing me, or you would have done that by now.” Light started wool gathering out loud, “And Shinigami doesn’t care about humanity at large as long as there are enough left for you to kill for life spans, and I haven’t gotten rid of that many…” He hummed and looked to fall into his own mind, not because he was concerned for Ryuk, the god guessed, but because his Utopia might be threatened.

“Brother?” Sayu, the nicer sibling according to Ryuk, who knew Light beyond the plastic face he showed the world, was knocking on the door. And there it was: that overly pleasant mask that slid in place and hid Lights ruthless megalomania and raging misanthropy from the world. Ryuk thought the trait to hide so well was one of the things that first made Light such an interesting human to follow around, now it just high-lighted how little this young man actually cared for anything beyond his own ambition.

“Come in, Sayu!” He called, and as she stepped into the room, he smiled at her, winningly, while tipping his head, causing his hair to flutter; completely disarming, completely calculated.

“I thought I heard voices?” She looked around the room with the curiosity of a regular teenager without the weight of genius level psychopathy driving her forward. Ryuk had read up on a lot of things human since he’d arrived here to fuck around with Light and other humans in general, and he almost felt grateful for it now; he was depending on one to remain alive.

“I’m talking to myself, it helps memorization, you might want to try it sometime.” Light’s subtle jab at Sayu’s academic performance was enough of a distraction; it set her off immediately – she screamed something about her brother being mean and how not everyone could be Japan’s best student. Ryuk knew she had that right: Light had glowed for days when a stack of acceptance letters, with matching lists of perks, had landed on his desk – apparently the prestige of snagging the top-ranking student, nationally, was a boon for any university – probably because Light would drag up the bell curve for any class, he took without eve trying. Wait, that was it; Light loved being praised for his brilliance! Ryuk would have to be very attentive to his moves and wants so he could complement him appropriately without seeming desperate – although Ryuk knew he was indeed desperate.

The despair that had settled across his mind was lifting, and Ryuk felt an emotion he could never remember feeling before; hope. At least he wasn’t bored anymore, damn that King and his ass brained ideas. Ryuk ignored the two siblings as they bickered over academic results – Sayu would get frustrated and leave soon enough.

The door clicked shut and Sayu left, which drew Ryuk out of his stupor.

“You usually try to make me trip up in front of my family, something is different.” And this was the moment Ryuk really realized why they’d called in L to investigate the Kira killings – even by inaction Ryuk had damned himself according to Light.

“I can’t say.” Ryuk said again, safe in the knowledge that he’d rather die a slow death than through the infinite tortures the King would visit upon him if he squealed.

“Can you show me?” Light tried probing for more information.

“I probably could, but ya ain’t the most receptive person out there, and if I didn’t get to explain it all, which I can’t, you’d say no, and I’d die.” Ryuk hated having to explain himself to a mere human, hated it, even if Light was an interesting little sonofabitch.

“So, you can die.” A maniacal gleam entered Light’s eyes.

“Only if we kill to protect a human or the King kills us.” Ryuk clarified, and almost felt insulted that the gleam in Light’s eyes disappeared.

“I would have thought you’d be more reticent with your information, getting anything out of you is usually light pulling teeth.” Light was still pondering.

“Well, ya know, Light-o, being threatened with death changes a God.” Ryuk snarked, sounding a little bit more like himself.

“So, I hold your life in my hands.” Light said with a breathless awe.

“Yeah, and you get off on that shit, don’t ya” Ryuk griped before he realized something “Hey, how did ya come ‘round to that?”

“I had a theory, which you just confirmed.” Light was a smug little shit, and if the King hadn’t specified _willing_ , the bastard, Light would have been face down ass up a good fifteen minutes ago.

“And you’re right, I do get a certain thrill when I hold people’s fate in my hands – I am God, and I should enjoy it, no?” And there was that pesky megalomania and narcissism again – sometimes Ryuk felt that all L had to do to stop Kira was put a full-size mirror in front of Light, who would then admire himself and his accomplishments until he starved to death. Of course, Light had more willpower than that, but it was a funny thought. Light retreated back into his own head and mulled the problem over, Ryuk could see it in the way his forehead bunched up and he started mouthing at the side of his left index finger – even the God of the New World had unseemly habits, and Ryuk had, up until recently, lorded it over Light because he could.

“No way.” Light paused, after a good while of thought. “No way, you are dead Ryuk, there is no way.” He muttered before looking at the Shinigami floating in front of him.

“What did yer little brain come up with.”

“You were ordered to fuck me.” The words almost knocked the breath out of Ryuk, and he didn’t even need to breathe, and it seems Light had caught it. “Oh god, I was right!” He whispered as he put his head in his hands.

“How did you come to that conclusion so easily?” Honestly, it was almost too good of a guess.

“You had orders from the King you couldn’t tell me about, under the threat of death, involving me, and not killing me, I would be dead, and since you said I wouldn’t agree without knowing the full specter, which was something you wouldn’t share, it would have to be something unpleasant, deeply unpleasant, and considering you Shinigami have no care for humans and our comings and goings I came up with sex and torture, but I have no motive.” Light was actually babbling, not the concise explanations he usually imparted with charismatic flourish. “I wasn’t sure, I guessed sex just to test the waters – again, you confirmed my hypotheses, but why?”

“You’ve amassed spiritual energy and by breeding you we’ll create new Shinigami.” Ryuk finally decided on telling what he could, even if he had to leave out the good parts.

“ _Breeding me?_ Do I look like a woman to you?” That was the closest thing Ryuk had heard Light come to actually shrieking.

“Gender doesn’t matter when it comes to death gods, Light-o. You’ve killed so many people you’re absolutely bursting with energy.”

“If I don’t do it?” Light asked.

“I die, eventually – I have lifespan saved up.” God Ryuk hated this.

“Your Note?”

“The King nullified it.”

“Shit…” Light whispered and got a calculating look in his eyes. Ryuk had a feeling he might have put a few bumps in the road for Light’s Utopian vision. Also: he was delighted to know Light could actually curse, that prissy bitch exterior was a bit sickening.

“Wait, if I’m a threat to your life, why haven’t you taken what you need by force?” Light looked Ryuk up and down, and it was almost like he was seeing how dangerous Ryuk could be for the first time. Ryuk curled his lips in distaste and looked away.

“Oh, you bastard, you _want_ to, but you can’t! Was that another order?” Light demanded angrily, his eyes were blazing, beautiful and vibrant. Ryuk had to resist the urge to pluck them out of his insolent skull. The entire Shinigami realm was probably laughing at him right now.

“You needed to be willing.” Ryuk ground out, because this entire situation was completely ridiculous. If it hadn’t been for that stupid rule, he would have taken Light somewhere secluded and ravaged his body until all he could do was bleed and cry.

“So, your King is mad at you.” Light probed.

“What gave you that idea?” Ryuk snarled.

“I need a picture of the situation, so I know how to proceed!” Light growled, and Ryuk was almost tempted to smash the kid’s head in; he was facing death, all Light was facing was a chance of having to dial back his damn murder spree.

“Oh, poor you.” Sarcasm was one of Ryuk’s favorite things about humans.

“Are there any benefits?” Light asked.

“To what?” Because that was an incomplete sentence if Ryuk ever heard one.

“To eating bacon every morning, no Ryuk, to being _bred_! What are we talking about, you moron, breakfast or ballet? I want to know why an otherworldly King wants me to get fucked by a God of Death!” Light’s speech was positively sibilant by the end of his little rant, and Ryuk could understand why – there was a reason he’d had to fuck his partners into submission before; Shinigami, who were brutish, cruel and ugly by nature, didn’t ask, they took. Ryuk shrugged in response, that was the bit where this entire thing got a little hairy; he wasn’t allowed to tell Light that being mated to Ryuk would give him access to most Shinigami powers at will.

“So, there are perks, but you can’t tell me about them.” Light made another contemplative sound. “And you’ve pissed off the king?” Ryuk nodded.

“I accept.” The words sounded wrong in Ryuk’s ears.


	2. Are you mating with my mate, mate?

**Summary for the Chapter:**

> The two of them complete their bonding.

**Notes for the Chapter:**

> I like this, how fucked up on a scale from 10-20 am I? No, I don't get the 1-9, that's for people that don't write shit like this.

“What?” He was pretty sure he was dreaming.

“I accept – if the king thought you not telling me about the benefits to being bred would be enough for me to say no, they have to be good, which means that I will gain something, I am hoping the eyes, and in return you will owe me as I am… carrying your children?” That last part ended in a question.

“Not carry, just birth. When I breed you it will be a signal for your stored energies to converge where my spunk spatters,” Light looked disgusted and Ryuk reveled in it “It’s better to do it inside so they don’t converge into an ungainly shape – mostly they turn into larvae who then feed on energies or other Shinigami to grow stronger, you’ll just have to push them out and I’ll transport them to the Shinigami realm. None of this nine months business you humans deal with.”

“Shinigami eat other Shinigami?” Light asked.

“To gain power.” Ryuk answered, and Light got that calculating gaze in his eyes that meant doom for someone.

“I have a plan, and it involves ruling the world and getting back at that stupid King for involving me.” Ryuk would have felt some kind of indignation for not being included in that consideration, but if Light had come up with a way to get back at the King, he was willing to risk it – the Old Man had gone too far this time, despite Ryuk’s slight fondness for him.

“Do tell, o Light-o, I’m all ears.” Ryuk could feel himself grin and was deeply happy that other Shinigami could only watch through the viewing pools and not hear – even the King of Death could be avoided by placing a few sleeping skulls and casting a few spells. “I just need to set up some privacy wards.”

“Privacy wards?” Light asked, bewildered.

“Shinigami magic” Ryuk winked before he blinked out of the human world – it was time to gather some sleeper skulls, death dust, and other little supplies. Most Shinigami hadn’t bothered to learn the old ways and the death magics, but Ryuk was always bored and learned it just to stave off the boredom. His supplies were right where he left them, and he knew enough of the Shinigami realm to avoid the usual haunts of the others. He appeared back in front of light with a sack filled to the brim with supplies.

“This will hide us from both mortals and gods, unless they know exactly where to look.” He looked at Light with a grin, who, surprisingly, grinned back.

“Set up the wards and I’ll tell you my plan.” Light commanded, and Ryuk had no reason not to comply. He arranged two skulls under Light’s bed and drizzled a circle of death dust around them before pricking his finger on one of his talons and drawing a design on each of the skulls. A chill went through the room and the sounds from outside seemed muted.

“The wards are active, if anyone are scrying us in the viewing pools, they’ll see us, but ain’t no way they’ll hear us, and even the sight might be a bit blurry.”

“I want you to eat our offspring.” Light said, without preamble. “If I let you breed me, I want you to eat our offspring and take over as Shinigami King if you get powerful enough. You Shinigami are all about deals,” he continued “Did the King specify that you weren’t allowed to eat the larvae?” Ryuk shook his head and marveled at Light: he would never have thought of that loophole – he’d been too angry at being forced into this.

 “You breed me-” Light started.

“I mate you and make you mine.” Cut in with a rumble – Light’s ruthlessness was attractive, the fact that he was willing to sacrifice their own spawn to gain power was absolutely breathtaking.

“Yes, that.” Light tried to seem unaffected, but the slight dusting of pink that graced his cheeks made Ryuk salivate. Apparently Light wasn’t as put together as he seemed to be.

“Have you mated before?” Ryuk asked, out of the blue.

“Have I.. no, I have not” Light seemed to want to squirm, but he held himself together admirably.

“I have usually only taken what I needed and left my victims broken and bleeding.” Ryuk said, plainly. “If you’re to be my mate I can’t have you damaged, we’ll need supplies.” The faint tinge of pink that had brightened Light’s cheeks turned scarlet, but he glared virulently.

“So, you’re a serial rapist.” Light growled out.

“And you’re a serial killer.” Ryuk countered, unaffected – human values were useless at best. Light snorted and flicked his hair imperiously.

“There are shops that cater to our needs, you’ll need to steal the supplies – I will not be caught dead purchasing them.” Light ordered. Ryuk realized that his upcoming mate was still planning on keeping his public persona, which wasn’t as bad as it sounded, as Ryuk had already seen Light at his worst, and if he wanted to put on some socially accepted spackle to cover that up for even longer then Ryuk wouldn’t mind. After Light had been mated and bred, they would have forever to exact their revenge.

“I wouldn’t know what to look for.” Ryuk admitted. Light snapped his fingers, went over to his laptop, opened up a few secure VPN browsers and looked up a dilator set, looked pointedly at Ryuk’s claws, and found an appropriately sized bottle of lube.

“You seem to know what you want.” The Shinigami commented.

“I have experimented a little and browsed.” Light seemed to have shed a lot of the human need to veil inappropriate subjects – of course, Light had also just proposed that he be bred and that Ryuk eat their energy offspring. His mate would be truly special once the changes set in – and then Light would have to learn to control them.

They planned to complete their bonding around Obon, which was the 13th to 16th of August which was right up against a weekend. Light’s father was always at work and Sayu and Light’s mother would be visiting Light’s grandmother, as per tradition, for six days. Light had begged off in favor of studying, which made his mother smile and Sayu called him boring. His father had smiled proudly. Ryuk had gathered the supplies, and an extra size up – Light had asked why until Ryuk unbuttoned his leather trousers and showed off his flaccid dick. Light had understood then. Everything was set, and Ryuk was hoping to fuck Light well enough to get most of the spirit energy out during the week. As Light had only kept killing with the Note, his stores had increased exponentially and Ryuk couldn’t wait for the mating itself. After they’d been mated all the King’s restrictions would fall by the wayside as the two of them would be bonded forever, in mind and body, as such, hiding things from Light would be impossible, which meant Light would know that he would become half Shinigami. That was when Ryuk would offer to share the flesh of their offspring – taking on the Shinigami King would be difficult, but if his mate was also powerful, they would be two, and Ryuk wouldn’t have to worry about his own life being ended through Light if the King or his cohorts got to him.

The day finally arrived, Sayu and their mother were packed and shipped off on the train, Soichiro was headed to the office with a weekend bag as he had no intention of stopping off at home, and Light’s dilator set was prepped and ready under the bed alongside the lube and some towels. This would be a novel experience for both Light and Ryuk, Ryuk because he had never had a willing partner, Light because this would be his first in so many ways. If anyone had ever told him a few months ago that his virginities would be taken by a mythological monster, he would have written down a horribly humiliating death without preamble, crime or no. Light made sure to lock all the doors and close all the windows, closing the curtains and turning the house into a shield against the outside world. Ryuk worked his magic and made the entire structure unnoticeable. Important services like the mail would still be able to find it as they were actively looking for the address, but people randomly wandering by, mortal or god, would easily dismiss it without thought.

“Are you ready then?” A naked Ryuk said to an equally naked Light. Ryuk looked odd without all his belts and accoutrements, but his legs, crotch, and cock were as black as his torso, his only pale skin was neck up, and that was held together by stitches.

“As I’ll ever be.” Light said without the exact excitement one would expect from someone about to lose their virginity. He was buck naked, and all of his pale, creamy skin was on display, and he looked like a ripe peach Ryuk wanted to bite into and tear to pieces. He would bite Light, but to form a bond, not to eat him, though his body looked good enough to devour in a single sitting. Light put down a towel on the bed and laid down upon it, next to the dilators, lube and the larger dildo that would come at the end.

“Do you want me to do it?” Light asked, Ryuk shook his head, he crawled into bed, for once, and let his form be physical, so he could feel the mattress dip under his knees, an unknown sensation. Light then crossed his arms and laid his head down on top of it. It felt very clinical, Ryuk thought, and Light could keep his calm for however long Ryuk let him: the Shinigami planned to leave his mate a wanton mess by the end of it, incomplete and begging unless he was stuffed to the brim with Shinigami cock or birthing out Shinigami larvae. The Shinigami fumbled a bit with the lube but managed to drizzle a cold stream down Light’s lightly fuzzed crack, watching the viscous liquid run between those pert cheeks. He left the tube uncapped, he would definitely need more. He then grabbed the smallest of the set, barely a finger thick, and rubbed it up and down between Light’s cheeks, coating the tip in lube, before locating the sphincter and pushing it, slowly. It slid in without a hitch, and Light barely moved when he fucked it in and out a few times. Ryuk drizzled some more lube and used the dilator to push it inside in a gush.

“I’m a virgin, not glass, when it feels smooth like this you size up.” Light said impatiently – apparently Light wasn’t lying when he said he liked anal play. Ryuk could smell excitement but not direct arousal. He drizzled some more lube straight into Light’s hole when he removed the first dilator and got to work on the second one, then the third, and by the time Ryuk had worked his way up to the fourth, Light was panting, making some cute mewling noises that made Ryuk’s blood burn, and his rim looked pink and puffy where it grabbed at the toy. Ryuk pushed down a bit to hard and Light bit out a curse.

“Was that the good spot you told me about?” Ryuk asked, seeing this as the perfect way in under Light’s skin on the quest to wreck his carefully built composure.

“Yes.” Light hissed, desperately trying to keep his voice level. Ryuk grinned and used the same angle on the next push in, which made Light tremble – his body didn’t lie even if his mouth was an absolute deceiver. Ryuk abused this knowledge ruthlessly as he sized up again, the last dilator before the final toy. If Light had been a cat he would be purring deeply, but he was only human as of yet, and as Ryuk worked the dildo inside, a black silicone monster which matched Ryuk for color and almost for size, the Shinigami felt his own anticipation skyrocket – Light parted so beautifully for him, and his little hole had expanded, puffed up and looked absolutely delectable. Ryuk had taken a lot of men, in a tangle of tears, pleading and blood, this quiet unfurling with Light was almost ethereal in its movements – Light would be begging by the end of the night, but not for Ryuk to stop.

“Are you ready to be mated and bred?” Ryuk rumbled as he extracted the dildo from Light – the puffy rim clutched at the silicone, reluctant to let it go, and Ryuk wanted to sink his cock inside so badly he could almost taste it.

“Yes.” Light answered simply, even with a flush of arousal from his cheeks down past his pert ass, hair in disarray and pupils blown wide. Ryuk grinned, it wouldn’t take much to rid this pesky little narcissist of all composure, Light looked gorgeous when he was disheveled. Ryuk slicked his own cock, groaning at how good it felt after having ignored it for so long. He set the spongy head to Light’s entrance and pushed, watched how it stretched and swallowed the bulbous head, and continued to take, take, take, until Ryuk’s cock was swallowed completely, the Shinigami’s weight pinning light to the bed. His mate was tight.

“Move.” Light commanded.

“No, I am not fucking you like this, you want this to be over with, I want you to enjoy it. I want you screaming.” Ryuk rumbled as he worked his knees in under Light’s hips and lifted Light, so his back was cradled against his larger chest. Gravity did some excellent work and forced him deeper.

“Do you feel me now, Light, my mate, Kira?” Ryuk growled. “You’ll be my mate, you will birth our children, and we’ll eat them together in a mad bid for power, now hang on to your sanity, I’m about to do my best to fuck you into the prettiest little slut I know you can be.” And without asking, Ryuk hoisted Light’s thigs up on his fore arms, tilting Light backwards into his chest – the benefits of being much larger than your partner – and began fucking up into Light’s tight body without restraint.  

 

There were no noises beyond the sick slap of skin against skin, and Ryuk had hoped for more, but then he caught a glimpse of Light’s straining face – he was holding it in, and it infuriated the Shinigami, who was finally fucking his way back into his own killing abilities. He briefly let go of one of Light’s thigs and slapped him across the face as well as he could manage, they were chest to back after all. The slap shocked Light and he was about to protest, but Ryuk was quicker, he grabbed the thigh again and set a ruthless pace. Lo and behold: the angels sang, the skies opened, and Light moaned like a cheap filthy whore.

“There we are, you little slut.” Ryuk growled into Light’s neck, breathing in the scent of arousal and desperation – Light was even better than Ryuk could ever have imagined, his pale arms had reached back and tangled around Ryuk’s neck, but he was too far gone to get a good grip, he was just hanging on as the Shinigami fucked unto him like a living toy. An idea formed in Ryuk’s head: he saw the mirror on Light’s closet door and moved off the bed, lifting and carrying Light easily. His mate was so far gone he barely noticed that Ryuk had stilled, temporary, dick still buried deep.

“Look, Light, look at you.” Ryuk nudged Light’s head with his nose to get him to pay attention, and eventually he got a glimpse of the mirror, where an image anyone else who knew of Light Yagami would never have imagined. The once so proper boy was a flushed mess, claw marks around his hips, bruises on his neck, dick leaking fluids everywhere, and ass stretched around a huge cock belonging to the monster who was lifting him up and down so he could see how obscenely his sphincter dragged against Ryuk’s cock on every upward turn.

“My pretty slut.” Ryuk whispered before he whirled around and flung them both onto the bed, legs handing off to the side. He reached around and wrapped his fingers, careful of the claws, around Light’s cock, and jackhammered into his mate so hard the bed made ominous creaking sounds, which were only drowned out by Light’s wails as he came. Ryuk took the opportunity to bite down on Light’s neck as he barreled towards his own orgasm. He groaned around his mouthful of blood as he thrust deep and spent – it had been decades since last time, and he had more than enough to give. He then punctured his own wrist and held it up to Light’s mouth.

“Sweat, blood, and come, let us be mates.” He spoke as Light latched on to the wound and drank desperately.

Ryuk eventually pulled out as Light drank, lapping at Light’s throat wound before he shuffled them onto the bed. Light wouldn’t gain his features just yet, and still needed mortal comforts. He stared down at the cheeks, who had up until recently, been parted around his cock and how nicely they fit back together, a steady trickle of white oozing out between them.

“I knew you had it in you.” Ryuk teased as Light finished dinking.

“Don’t get cocky.” Light hissed.

“Don’t be mean, Light-o.” Ryuk laughed as he nuzzled down into the bed and pulled Light to his chest. “We’re mated now, which means we have an eternity to get along.”

“An eternity?” Light queried.

“I couldn’t tell you before the mating but being mated to one of us gives you powers – the king didn’t want a lust for power to make you willing, so I was forbidden to speak, but you figured it out, partly, my clever little mate.” Ryuk purred “You’ll get the eyes, the wings, immortality, and as long as one of us is alive none of us can die. We’ll be able to read each other’s thoughts, eventually. You’ll need to learn to appear human again, however.” Ryuk lazily explained. He watched a cruel smile spread across Light’s face.

“I am going to win.” He cackled, a mad glint in his eyes. Ryuk knew who his mate referred to and cackled alongside Light: only his mate would think about world domination with cum still leaking out of his ass after getting freshly fucked, Ryuk adored it.

“That you are.” Ryuk agreed, finally, and they both looked at each other and smiled, teeth and madness, ready for the world.


	3. Eating Babies is not just for Cronos

**Summary for the Chapter:**

> The two of them view the result of their consummation, and eat it to gain power.

**Notes for the Chapter:**

> And we kick it into high gear. I need forgiveness.

They had fallen asleep on the bed, Ryuk was sated like a cat in a sunbeam and had taken advantage, Light was wrung out and barely able to stay conscious. They woke a few hours later when Light rolled over and started – his stomach was distended.

“Ryuk.” He hissed before reaching over and waking his mate. At hearing the hiss and feeling the faint distress of his mate in the back of his head, the Shinigami rolled over and blinked awake, unused to succumbing to bodily needs and sleeping when in the mortal world. He saw his beautiful mate, who had already begun to change, staring down at his swollen stomach in shock. His flat stomach was now drum tight, and something moved under the skin. Ryuk drank in the sight of his mate and grinned; in addition to his filled abdomen, he’d changed, noticeably – his brown eyes were now rubies, his face was even sharper, and as his mouth kept open in shock, Ryuk saw fangs. He also saw his hair had lengthened.

“You’re ready to give birth to our first larvae, and you’ve started transforming yourself.” Ryuk said looking Light up and down again, he even saw slits starting to form behind Light’s shoulder blades, the wings were going to come in. Another fluid exchange and phenomenal shag would probably make them pop out in full.

“Ready to birth? And what changes?”  Light almost looked his age, and not like an adult corporate shark ready to do whatever to complete his goals trapped in an eighteen-year-old body.

“You’ve got a miasma of death energy around you, and I hadn’t blown my load in forever, and that has made our little power snack grow really well.” Ryuk cooked as he stroked across Light’s belly, “Luckily I fucked you open really good, it might just slip out all by its own.” Light blushed and didn’t say anything. “And you’re turning into a Shinigami mate, look into the mirror.” Ryuk gestured to the mirror and Light managed to stagger to his knees, even with his changed gravity center, and look in the mirror. A shocked noise knotted in the back of his throat, and Ryuk loved the look of awe plastered across his face as Light touched his own face to really check if it was his own reflection.

“You are _beautiful_.” Ryuk murmured as he put a clawed hand on Light’s bump, watching his mate explore his new looks in the mirror. And it was true; Light looked too fragile as a human, looked too polished, looked too put together, but here, with his claws coming in, eyes of a predator in his sockets, wild hair, and fangs, he looked like a burgeoning hunter – even with the larva squirming under his skin.

“I feel more like myself.” Light whispered, as he traced his skin with his growing claws, raising thin red lines.

“You were always a predator, now you look like it.” The death god said – he felt a flutter of something positive in the back of his head, and in the depths of his heart – both he and Light were feeling this positivity wash over them. He wondered if this was what mortals called peace.

They sat like this for a good long while, but suddenly Light doubled over and groaned low.

“I think it’s coming out.” Light whispered as he curled over Ryuk, who began to stroke his back, soothingly.

“Do you feel pressure or is it only moving?” Ryuk cooed as Light sprawled across his midriff.

“Pressure.” Light was groaning. “It’s moving downwards.” His mate spread his legs instinctively, and Ryuk knew that soon it would peak, and he’d have to pull it out – it was probably nothing more than a gelatinous blob but packed with enough spirit energy to give both of them a significant power boost.

“It feels like… like…” Light whimpered and cut off his sentence, his face flaring red while trying to hide his gaze from Ryuk, who did nothing but pay attention to his uncomfortable mate. He reached a hand up to lights hole, careful with the claws, which was still sloppy with lube and come, and felt it twitch against his fingers. Soon. He eventually felt their larvae wiggle against the pads of his fingers, and as it crested, Light whined pitifully, and Ryuk could smell his embarrassment. Ryuk clamped two fingers around the thing and pulled it out in a wet squelch of fluids, leaving Light empty and groaning.

“Look, this is the very start of all Shinigami.” Ryuk declared as the larvae squirmed and whined in his grasp. It was long, translucent with a black tinge, and you could barely see a mouth of some kind on one end.

“That’s pathetic.” Light said with a scoff before he looked down at his stomach, which was now very flat again.

“Want to break it open?” Ryuk said, licking his lips – he could smell the energies contained in this larvae, and it was enough to make him antsy.

“Wash it first.” Light commanded as he swept the toys of the bed and used the already stained towel to clean himself up a bit before flopping down onto the bed and rolling himself into a soft cocoon. His mind was brilliant, but still catching up to the fact that he was now, apparently, half Shinigami, and had just given birth to a larvae.  He’d seen the eyes though, and his own name floating above his head in the mirror – he’d gotten the eyes and immortality all in one fell swoop. He hoped Rem never thought of mating Misa, then they would be awful to get rid of, and Light really wanted to watch them both burn.

Ryuk had left for the bathroom – he wouldn’t have hesitated if he were the only one consuming it, but his mate demanded he clean the thing, and so he wood – Light had essentially saved him from certain death and given him a spectacular shag in one fell swoop. If that meant being a little pickier about what he put in his mouth it really wasn’t that big of a deal. The larvae squealed as he doused it with water. When he returned to the room, he saw light bundled up nice and tight with a little smile on his face – the contentment he felt in the back of his mind was immense, and it showed that their mental link was forming on schedule. Eventually they would be able to communicate telepathically.

“Our mental link is progressing well, I can feel your contentment.” Ryuk said as he walked into Light’s bedroom. Light blinked and smiled; he probably noticed the wave of positivity Ryuk was producing.

“Come, let me look at it.” Light demanded. The Shinigami plopped down beside his mate, still holding the wiggling thing in his grasp. Light untangled his hands, snagged his claws on the sheets briefly, and held them out to accept his larvae.

“It smells delicious” Light whispered – it smelled like energy, power, and all things he strived for in life.

“You’re becoming a halfie, a lot of smells and tastes are enhanced and expanded, you can smell power as a Shinigami, and you’ll want to eat it.” Ryuk confirmed as he stroked across the larvae. It was bittersweet – this was the first one he had ever produced, yet the chance to get back at the King of Death was a great need. It would also help Light solidify his control over his new powers so he could return to looking human and return to dominating this world.

“How do we eat it?” Light asked, a curious glint to his eyes.

“When we kill it, it’s going to start disintegrating immediately, so we just need to break it in half and swallow.” Ryuk said, scratching his face, wondering how they would do that without loosing too much of that precious energy.

“We’ll start swallowing an end each and bite when our lips meet.” Light chimed in, probably noting Ryuk’s confused expression.

“How romantic.” Ryuk grinned.

“How practical.” Light shot him down – just because he’d gotten all of his wildest dreams served on a platter, alongside a hung Shinigami who he really didn’t know he’d wanted until he’d been had, didn’t mean that Light Yagami was planning on being swallowed up by sentiment and non-practicalities.

He picked up the larvae with his thumb and index finger and lifted it in the air, attempting to catch one end with his mouth so Ryuk could catch the other. The Shinigami moved to help his mate by steadying one end and feeding the other into his own mouth, as he had two hands available. They both swallowed their way closer, it was much easier to do things like this, Light realized, when he had no actual need for air. Their lips met, in their first kiss, and both of them bit down, fangs tearing through the soft skin of the larvae as flavor exploded in both their mouths; they swallowed, but in stead of moving apart, Ryuk grabbed Light’s head and pulled him close. He was determined to be all of his mates’ firsts, and all of his mates lasts – he wanted to possess Light completely, in every way. The power from the larvae exploded when it hit their stomachs, and the pleasure of the energy tingling from their cores to their extremities was intoxicating.

“Want to make another?” Ryuk pulled away to ask with a grin across his face – his eyes were brighter and his hair longer, and his shoulders felt broader. Light grinned, high on the power rush, as he felt his muscles strengthen and saw his eyesight sharpen.

“Yes, it’s a pleasurable way to obtain power.” Light hummed as his head swam.

“I’ll make you a hedonist, eventually.” Ryuk rumbled as he shifted them around, laying Light flat on his back and settling between his thighs – the rush had left them both hard.

“Work hard, play hard.” Light countered as Ryuk licked his way down Light’s throat.

“All work and no play makes Light a dull boy.” Ryuk hummed before he bit down on Light’s left pectoral, laving at the welling blood with relish. Light grabbed Ryuk’s head and pushed his face into the wound – apparently the transformation had crossed a few wires between pleasure and pain as pleasure frizzed up Light’s spine.

“If you want to get technical, _mate_ ,” Light growled, using Ryuk’s title, “We are producing power for our eventual domination of two worlds, we are just doing it in a pleasurable manner.” Light moaned that last bit as Ryuk sunk his teeth into his stomach – only to bite, not to rip.

“Ah, but combining work and pleasure is the best way to work.” Ryuk sassed, before he bent down, teeth and all and folded Light’s dick and balls into his large mouth with his tongue, causing his young mate to jack-knife and moan, scrabbling for purchase in Ryuk’s coarse hair.

“I just need to get the job done.” Light gasped, trying his best to keep his composure, and failed with a broken moan as Ryuk swallowed around him. Ryuk liked breaking Light’s composure, it had been an amusing activity ever since Light had picked up the notebook, but now, breaking it in this manner, that was the most fun Ryuk could remember having, ever.

“Fuck me” Light demanded, as he pulled at Ryuk’s hair with his newly found superhuman strength; Ryuk should have realized that Light would be bossy in bed after his first rodeo – his mate was a quick study.   

“As my mate commands.” Ryuk responded after he pulled off Light’s dick. It flopped onto his stomach, slick with spit and straining. Ryuk himself raised up and stroked his own cock twice before crowding in on his little mate once more – Light was probably gagging for it; Ryuk himself had been insatiable for years after having eaten himself to consciousness, he’d raped and pillaged his way across the world until the King himself had stepped in and made him calm down. Apparently, humans noticed when their sons and daughters were violated, hanging in thin air and spread open.

Sliding back inside was heaven – Light was still soft and plush, and offered little resistance as Ryuk moved. What sealed the deal for Ryuk, however, was the gratified moan Light deigned to share when he bottomed out. Having a willing partner was so much better; why hadn’t he thought of this before? Of course, then he might have ended up with some simpering sycophant and not this wildly driven creature beneath him. No; Light Yagami was worth the wait – and it wasn’t love, it couldn’t be, as Ryuk had never known that emotion, but it was knowledge that he now had a permanent ally, and that world, both of them, would tremble at their feet.

“A toast: to world conquest” Light groaned as he looked into Ryuk’s eyes.

“To world conquest.” Ryuk answered brightly.

They sealed the deal with a kiss.


End file.
